A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates, generally, to medical devices and medical device manufacturing apparatus and methods. Additionally, the invention relates to holding, compressing, and crimping devices. More particularly, the invention relates to medical stent crimping devices. The invention has particular utility in the medical industry as a device and method for uniformly crimping a balloon expandable or self-expanding metal or non-metallic stents or stent grafts.
2. Background Information
The state of the art includes various stent crimping devices and methods. The devices include a collet style crimp mechanism, a flat rolling plate style crimp mechanism, loop or coil radial compression (U.S. Pat. No. 6,063,102), a funnel tube style crimping mechanism (U.S. Pat. No. 5,992,000 FIG. 3), a Touhy style silicone elastomeric crimp sleeve (U.S. Pat. No. 6,009,614), and an expandable bladder/elastic tube. The flat rolling plate style crimp mechanism includes an elastomeric surface upon which the stent in place, and a flat plate positioned and adapted to roll over the stent. Weight may be added onto the plate. The rolling action crimps the stent in place somewhat akin to rolling out dough. The expandable bladder is shaped as a sleeve. Fluid is pumped into the bladder to rotatably compress the stent positioned in it. Other U.S. Patents directed to stent crimping technology include U.S. Pat. Nos. 6,063,092, 6,051,002, 6,024,737, 6,018,857, 5,951,540, 5,931,851, 5,672,169, 5,672,169 and 5,626,604. These patents provide background information on stent technology in general and are incorporated by reference for that reason.
The known stent crimper devices and methods are believed to have significant limitations and shortcomings. For example, their structure (i.e. bore size in the structure) limits the diameter of the stent. Additionally, they are not able to use a simple process to satisfy the tolerance demands for certain medical applications. For example, they may not be able to accurately, consistently and uniformly crimp the stent in a single step. This is particularly true of stents with small diameters. For this and other reasons, a need exists for the present invention.
This invention provides a stent crimper device and method which are believed to fulfil the need and to constitute an improvement over the background technology. The device and method of the present invention makes it possible through a simple process to crimp a balloon expandable or self-expanding metal or non-metallic intravascular or other anatomically placed stents. The present invention does not require a fixed bore size (I.D.) to obtain the final crimped stent profile. The present invention can be designed to crimp operably receive stents having diameters from 30 mm to near zero. It has been found that, to optimize the present invention to crimp coronary stents, the device should be designed to handle stents between 0.5 mm to 5 mm. The present invention is capable of holding tolerances to 0.005xe2x80x3 while providing a uniform extended crimp of between 1 mm and 100 mm in length.
Benefits include a reduced cycle time, reduced machine size, repeatability of the crimped stent diameter, security of the crimped stent, and the elimination of a fixed bore size (I.D.) during the crimp process.
The present invention provides a crimping device and method which is well suited for crimping medical stents.
In one embodiment the apparatus for radially compressing an article, comprises:
a. at least one stationary member;
b. at least one rotatable member which is moveable in relation to the stationary member; and
c. at least three segments;
i. with a proximal end and an angled distal end with at least one angled side face terminating in an edge of a predetermined length, each segment having a centerline between the proximal and distal ends, each segment having a proximal point and a distal point, one said point being disposed on the centerline and one said point being disposed off the centerline, and one said point being pivotally coupled by pins to the stationary member and one said point being pivotally coupled by pins to the rotatable member;
ii. the segments being arranged so that the segment distal ends are disposed adjacent to and a predetermined distance away from a central point and defining a central aperture with a cylindrical dimension, and that the segment centerlines extending therefrom toward the segment distal ends are oriented away from the central point; and
iii. the segment distal ends moving closer to the central point upon rotation of the rotatable member in a predetermined direction.
The apparatus has a first state wherein the segment centerlines are tangentially oriented with respect to the central aperture, and a second state wherein the segment centerlines become radially aligned with respect to the center point and the aperture closes upon rotation of the rotatable member in the predetermined direction.
At least four basic arrangements of the proximal and distal points exists:
1. The segment distal point is on the center line and coupled to the rotatable member, and the segment proximal point is disposed off the centerline and coupled to the stationary member.
2. The segment distal point is on the center line and coupled to the stationary member, and the segment proximal point is disposed off the centerline and coupled to the rotatable member.
3. The segment distal point is off the center line and coupled to the rotatable member, and the segment proximal point is disposed on the centerline and coupled to the stationary member.
4. The segment distal point is off the center line and coupled to the stationary member, and the segment proximal point is disposed on the centerline and coupled to the rotatable member.
For each of these embodiments may be one stationary member and one rotatable member or two stationary members and two rotatable members.
The most preferred embodiment of the single stationary member, single rotatable member apparatus for crimping a stent by segmental radial compression, comprises:
a. a stationary base member;
b. a rotatable drive hub which is moveable in relation to the stationary base member; and
c. a crimping head aligned with respect to the stationary base member and to the rotatable drive hub, and including at least ten segments;
i. the segments each having a proximal end and an angled distal end with at least one angled side face terminating in an edge of a predetermined length, each segment having a centerline between the proximal and distal ends, each segment having a proximal point and a distal point, the distal point being disposed on the centerline and the proximal point being disposed off the centerline, and the proximal point being pivotally coupled by pins to the stationary base member and the distal point being pivotally coupled by pins to the rotatable hub member;
ii. the segments being arranged so that the segment distal ends are disposed adjacent to and a predetermined distance away from a central point and defining a central aperture with a cylindrical dimension, and that the segment centerlines extending therefrom toward the segment distal ends are oriented away from the central point; and
iii. the segment distal ends moving closer to the central point upon rotation of the rotatable hub member in a predetermined direction, whereby the stent is disposed around a base substrate, aligned in the central aperture and crimped around the base substrate upon rotation of the rotatable hub.
The most preferred embodiment of the dual stationary member, dual rotatable member apparatus for crimping a stent by segmental radial compression, comprises:
a. a pair of aligned, stationary base members separated a predetermined distance;
b. a pair of aligned rotatable drive hubs which are moveable in relation to the stationary base member and in synchronization with each other; and
c. a crimping head aligned with respect to the base members and the drive hubs, and including at least ten segments;
i. the segments each having a proximal end and an angled distal end with at least one angled side face terminating in an edge of a predetermined length, each segment having a centerline between the proximal and distal ends, each segment having a proximal point and a distal point, the distal point being disposed on the centerline and the proximal point being disposed off the centerline, and the proximal point being pivotally coupled by pins to the stationary base members and the distal point being pivotally coupled by pins to the rotatable hub members;
ii. the segments being arranged so that the segment distal ends are disposed adjacent to and a predetermined distance away from a central point and defining a central aperture with a cylindrical dimension, and that the segment centerlines extending therefrom toward the segment distal ends are oriented away from the central point; and
iii. the segment distal ends moving closer to the central point upon rotation of the rotatable hub members in a predetermined direction, whereby the stent is disposed around a base substrate, aligned in the central aperture and crimped round the base substrate upon rotation of the rotatable hub.
The invention also provides a method of compressing an article comprising the steps of:
a. providing an arrangement of a plurality of segments, each having a predetermined shape with a proximal end and an angled distal end with at least one angled side face terminating in an edge of a predetermined length, each segment having a centerline between the proximal and distal ends, each segment having a proximal point and a distal point, one said point being disposed on the centerline and one said point being disposed off the centerline, and one said point being pivotally coupled by pins to the stationary member and one said point being pivotally coupled by pins to the rotatable member, the segments being arranged so that the segment distal ends are disposed adjacent to and a predetermined distance away from a central point and defining a central aperture with a cylindrical dimension, and that the segment centerlines extending therefrom toward the segment distal ends are oriented away from the central point; and
b. placing a stent on a base substrate;
c. inserting the stent and base substrate into the central aperture; and
d. rotating the rotatable member in a predetermined direction so that the segment distal ends move closer to the central point, whereby the central aperture contacts, compresses and crimps the stent onto the base substrate.
The features, benefits and objects of this invention will become clear to those skilled in the art by reference to the following description, claims, and drawings.